1. Field of the Invention
The present invention relates to a broadcast data communications network, such as a network conforming to IEEE 802.3 FOIRL (Fiber Optic Inter-Repeater Link) standard and, more particularly, to an apparatus and method for implementing a redundancy control function in such a network.
2. Description of the Prior Art
U.S. Pat. No. 4,709,365 (Beale et al.) discloses a sequential (ring) data transmission network in which dual rings reconfigure into a single ting after a failure.
U.S. Pat. No. 4,809,264 (Abraham et al.) discloses a collision signal detection system for use in a data transmission network.
Properties of broadcast networks are described in IEEE 802.4-1985, Token Bus Access Method, page 55, items (1)-(5) and (7). Slot time terminology is defined in IEEE 802.3-1985 CSMA/CD Access Method, page 39, 56 and IEEE 802.4-1985, pages 56, 78
The fiber optic communication system apparatus sold by Chipcom Corporation, Southborough, Mass. as the ONline.TM. fiber module provides fiber optic connectivity between two stations operating in accordance with IEEE 802.3 10BASE-F draft standard. Both primary and secondary communications links are defined. The apparatus provides a redundancy control for fault recovery only in the event that the stations are communicating in the synchronous mode.
It is believed desirable to provide an arrangement able to provide redundancy;control for stations communicating over a broadcast network.